Effective thermal conductivity of packed bed adsorbers: Part 1 - Experimental study

Low thermal conductivity in packed bed adsorbers is a crucial challenge facing widespread adoption of low-grade heat adsorption thermal energy storage systems. In this work, thermal conductivities of 2-mm diameter AQSOA FAM-Z02 packed bed adsorbers with different numbers of adsorbent layers are measured, using a NETZSCH HFM 436/3/1E Lambda, in the temperature range of 10-80 °C and under atmospheric pressure. Effects of thermal contact resistance (TCR) between the adsorbent particles and the bed metal surfaces are deconvoluted from the total thermal resistance. Effective thermal conductivities of the adsorber packed bed are 0.188 and 0.204 W m−1 K−1 at temperatures of 10 and 80 °C, respectively. It is observed that the relative importance of TCR compared to the total thermal resistance of a monolayer FAM-Z02 packed bed, is 67% at 25 °C and under contact pressure of 0.7 kPa, which is significant and should be considered in the design of adsorption systems.